What i do to align my guide scope and my imaging scope is to use the target reticle in Metaguide and the centre cross in SGP Frame and Focus. Align the scope camera first to a star target, then adjust the guidescope to the same centred target. It works.

Another way is to use SGP Frame and Focus to align your imaging camera on the first scope first, then deselect the first imaging camera and select the second camera on the second scope, align the second scope. This assumes you have the ability to adjust the second scope without moving the mount (which is aligned on the star during step one).

If you want rotation to match, take a SGP Frame and Focus sample image with the first camera, then switch to the second in another window and rotate the second camera to get close to field orientation. Think of it an manual plate solving.

It's the mechanicals I've got more of a problem with my small scope is currently screwed to a dovetail which in turn is screwed to the top of the rings of my Esprit. It's just lacking the precision that would put my mind to rest.

Yep, that is the guidescope mount i use on my 10" Inaging Newt. It is very good at X and Y axis adjustment with my 60mm guidescope but i don't know how it would go with a heavier scope and camera. It has gotten abit sloppy in the two years i have been using it. It uses a nylon bushing and springs on each axis.

If i was piggy back mounting my TS80 and my TS115, i would be tempted to get one of these, in the appropriate size: